mdw@git.distorted.org.uk Git - catacomb-python/blob - catacomb/__init__.py

   1 # -*-python-*-
   2 #
   3 # $Id$
   4 #
   5 # Setup for Catacomb/Python bindings
   6 #
   7 # (c) 2004 Straylight/Edgeware
   8 #
   9
  10 #----- Licensing notice -----------------------------------------------------
  11 #
  12 # This file is part of the Python interface to Catacomb.
  13 #
  14 # Catacomb/Python is free software; you can redistribute it and/or modify
  15 # it under the terms of the GNU General Public License as published by
  16 # the Free Software Foundation; either version 2 of the License, or
  17 # (at your option) any later version.
  18 #
  19 # Catacomb/Python is distributed in the hope that it will be useful,
  20 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 # GNU General Public License for more details.
  23 #
  24 # You should have received a copy of the GNU General Public License
  25 # along with Catacomb/Python; if not, write to the Free Software Foundation,
  26 # Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27
  28 #----- Imports --------------------------------------------------------------
  29
  30 import _base
  31 import types as _types
  32 from binascii import hexlify as _hexify, unhexlify as _unhexify
  33 from sys import argv as _argv
  34
  35 #----- Basic stuff ----------------------------------------------------------
  36
  37 ## For the benefit of the default keyreporter, we need the program na,e.
  38 _base._ego(_argv[0])
  39
  40 ## Initialize the module.  Drag in the static methods of the various
  41 ## classes; create names for the various known crypto algorithms.
  42 def _init():
  43   d = globals()
  44   b = _base.__dict__;
  45   for i in b:
  46     if i[0] != '_':
  47       d[i] = b[i];
  48   for i in ['MP', 'GF', 'Field',
  49             'ECPt', 'ECPtCurve', 'ECCurve', 'ECInfo',
  50             'DHInfo', 'BinDHInfo', 'RSAPriv', 'BBSPriv',
  51             'PrimeFilter', 'RabinMiller',
  52             'Group', 'GE',
  53             'KeyData']:
  54     c = d[i]
  55     pre = '_' + i + '_'
  56     plen = len(pre)
  57     for j in b:
  58       if j[:plen] == pre:
  59         setattr(c, j[plen:], classmethod(b[j]))
  60   for i in [gcciphers, gchashes, gcmacs, gcprps]:
  61     for c in i.itervalues():
  62       d[c.name.replace('-', '_')] = c
  63   for c in gccrands.itervalues():
  64     d[c.name.replace('-', '_') + 'rand'] = c
  65 _init()
  66
  67 ## A handy function for our work: add the methods of a named class to an
  68 ## existing class.  This is how we write the Python-implemented parts of our
  69 ## mostly-C types.
  70 def _augment(c, cc):
  71   for i in cc.__dict__:
  72     a = cc.__dict__[i]
  73     if type(a) is _types.MethodType:
  74       a = a.im_func
  75     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
  76       continue
  77     setattr(c, i, a)
  78
  79 ## Parsing functions tend to return the object parsed and the remainder of
  80 ## the input.  This checks that the remainder is input and, if so, returns
  81 ## just the object.
  82 def _checkend(r):
  83   x, rest = r
  84   if rest != '':
  85     raise SyntaxError, 'junk at end of string'
  86   return x
  87
  88 #----- Bytestrings ----------------------------------------------------------
  89
  90 class _tmp:
  91   def fromhex(x):
  92     return ByteString(_unhexify(x))
  93   fromhex = staticmethod(fromhex)
  94   def __hex__(me):
  95     return _hexify(me)
  96   def __repr__(me):
  97     return 'bytes(%r)' % hex(me)
  98 _augment(ByteString, _tmp)
  99 bytes = ByteString.fromhex
 100
 101 #----- Multiprecision integers and binary polynomials -----------------------
 102
 103 class _tmp:
 104   def negp(x): return x < 0
 105   def posp(x): return x > 0
 106   def zerop(x): return x == 0
 107   def oddp(x): return x.testbit(0)
 108   def evenp(x): return not x.testbit(0)
 109   def mont(x): return MPMont(x)
 110   def barrett(x): return MPBarrett(x)
 111   def reduce(x): return MPReduce(x)
 112   def factorial(x):
 113     'factorial(X) -> X!'
 114     if x < 0: raise ValueError, 'factorial argument must be > 0'
 115     return MPMul.product(xrange(1, x + 1))
 116   factorial = staticmethod(factorial)
 117 _augment(MP, _tmp)
 118
 119 class _tmp:
 120   def zerop(x): return x == 0
 121   def reduce(x): return GFReduce(x)
 122   def trace(x, y): return x.reduce().trace(y)
 123   def halftrace(x, y): return x.reduce().halftrace(y)
 124   def modsqrt(x, y): return x.reduce().sqrt(y)
 125   def quadsolve(x, y): return x.reduce().quadsolve(y)
 126 _augment(GF, _tmp)
 127
 128 class _tmp:
 129   def product(*arg):
 130     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 131     return MPMul(*arg).done()
 132   product = staticmethod(product)
 133 _augment(MPMul, _tmp)
 134
 135 #----- Abstract fields ------------------------------------------------------
 136
 137 class _tmp:
 138   def fromstring(str): return _checkend(Field.parse(str))
 139   fromstring = staticmethod(fromstring)
 140 _augment(Field, _tmp)
 141
 142 class _tmp:
 143   def __repr__(me): return '%s(%sL)' % (type(me).__name__, me.p)
 144   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 145 _augment(PrimeField, _tmp)
 146
 147 class _tmp:
 148   def __repr__(me): return '%s(%sL)' % (type(me).__name__, hex(me.p))
 149   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 150 _augment(BinField, _tmp)
 151
 152 class _tmp:
 153   def __str__(me): return str(me.value)
 154   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 155 _augment(FE, _tmp)
 156
 157 #----- Elliptic curves ------------------------------------------------------
 158
 159 class _tmp:
 160   def __repr__(me):
 161     return '%s(%r, %s, %s)' % (type(me).__name__, me.field, me.a, me.b)
 162   def frombuf(me, s):
 163     return ecpt.frombuf(me, s)
 164   def fromraw(me, s):
 165     return ecpt.fromraw(me, s)
 166   def pt(me, *args):
 167     return me(*args)
 168 _augment(ECCurve, _tmp)
 169
 170 class _tmp:
 171   def __repr__(me):
 172     if not me: return 'ECPt()'
 173     return 'ECPt(%s, %s)' % (me.ix, me.iy)
 174   def __str__(me):
 175     if not me: return 'inf'
 176     return '(%s, %s)' % (me.ix, me.iy)
 177 _augment(ECPt, _tmp)
 178
 179 class _tmp:
 180   def __repr__(me):
 181     return 'ECInfo(curve = %r, G = %r, r = %s, h = %s)' % \
 182            (me.curve, me.G, me.r, me.h)
 183   def group(me):
 184     return ECGroup(me)
 185 _augment(ECInfo, _tmp)
 186
 187 class _tmp:
 188   def __repr__(me):
 189     if not me: return '%r()' % (me.curve)
 190     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 191   def __str__(me):
 192     if not me: return 'inf'
 193     return '(%s, %s)' % (me.x, me.y)
 194 _augment(ECPtCurve, _tmp)
 195
 196 #----- Key sizes ------------------------------------------------------------
 197
 198 class _tmp:
 199   def __repr__(me): return 'KeySZAny(%d)' % me.default
 200   def check(me, sz): return True
 201   def best(me, sz): return sz
 202 _augment(KeySZAny, _tmp)
 203
 204 class _tmp:
 205   def __repr__(me):
 206     return 'KeySZRange(%d, %d, %d, %d)' % \
 207            (me.default, me.min, me.max, me.mod)
 208   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 209   def best(me, sz):
 210     if sz < me.min: raise ValueError, 'key too small'
 211     elif sz > me.max: return me.max
 212     else: return sz - (sz % me.mod)
 213 _augment(KeySZRange, _tmp)
 214
 215 class _tmp:
 216   def __repr__(me): return 'KeySZSet(%d, %s)' % (me.default, me.set)
 217   def check(me, sz): return sz in me.set
 218   def best(me, sz):
 219     found = -1
 220     for i in me.set:
 221       if found < i <= sz: found = i
 222     if found < 0: raise ValueError, 'key too small'
 223     return found
 224 _augment(KeySZSet, _tmp)
 225
 226 #----- Abstract groups ------------------------------------------------------
 227
 228 class _tmp:
 229   def __repr__(me):
 230     return '%s(p = %s, r = %s, g = %s)' % \
 231            (type(me).__name__, me.p, me.r, me.g)
 232 _augment(FGInfo, _tmp)
 233
 234 class _tmp:
 235   def group(me): return PrimeGroup(me)
 236 _augment(DHInfo, _tmp)
 237
 238 class _tmp:
 239   def group(me): return BinGroup(me)
 240 _augment(BinDHInfo, _tmp)
 241
 242 class _tmp:
 243   def __repr__(me):
 244     return '%s(%r)' % (type(me).__name__, me.info)
 245 _augment(Group, _tmp)
 246
 247 class _tmp:
 248   def __repr__(me):
 249     return '%r(%r)' % (me.group, str(me))
 250 _augment(GE, _tmp)
 251
 252 #----- RSA encoding techniques ----------------------------------------------
 253
 254 class PKCS1Crypt (object):
 255   def __init__(me, ep = '', rng = rand):
 256     me.ep = ep
 257     me.rng = rng
 258   def encode(me, msg, nbits):
 259     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 260   def decode(me, ct, nbits):
 261     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 262
 263 class PKCS1Sig (object):
 264   def __init__(me, ep = '', rng = rand):
 265     me.ep = ep
 266     me.rng = rng
 267   def encode(me, msg, nbits):
 268     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 269   def decode(me, msg, sig, nbits):
 270     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 271
 272 class OAEP (object):
 273   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 274     me.mgf = mgf
 275     me.hash = hash
 276     me.ep = ep
 277     me.rng = rng
 278   def encode(me, msg, nbits):
 279     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 280   def decode(me, ct, nbits):
 281     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 282
 283 class PSS (object):
 284   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 285     me.mgf = mgf
 286     me.hash = hash
 287     if saltsz is None:
 288       saltsz = hash.hashsz
 289     me.saltsz = saltsz
 290     me.rng = rng
 291   def encode(me, msg, nbits):
 292     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 293   def decode(me, msg, sig, nbits):
 294     return _base._pss_decode(msg, sig, nbits,
 295                              me.mgf, me.hash, me.saltsz, me.rng)
 296
 297 class _tmp:
 298   def encrypt(me, msg, enc):
 299     return me.pubop(enc.encode(msg, me.n.nbits))
 300   def verify(me, msg, sig, enc):
 301     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 302     try:
 303       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 304       return x is None or x == msg
 305     except ValueError:
 306       return False
 307 _augment(RSAPub, _tmp)
 308
 309 class _tmp:
 310   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 311   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 312 _augment(RSAPriv, _tmp)
 313
 314 #----- Built-in named curves and prime groups -------------------------------
 315
 316 class _groupmap (object):
 317   def __init__(me, map, nth):
 318     me.map = map
 319     me.nth = nth
 320     me.i = [None] * (max(map.values()) + 1)
 321   def __repr__(me):
 322     return '{%s}' % ', '.join(['%r: %r' % (k, me[k]) for k in me])
 323   def __contains__(me, k):
 324     return k in me.map
 325   def __getitem__(me, k):
 326     i = me.map[k]
 327     if me.i[i] is None:
 328       me.i[i] = me.nth(i)
 329     return me.i[i]
 330   def __setitem__(me, k, v):
 331     raise TypeError, "immutable object"
 332   def __iter__(me):
 333     return iter(me.map)
 334   def iterkeys(me):
 335     return iter(me.map)
 336   def itervalues(me):
 337     for k in me:
 338       yield me[k]
 339   def iteritems(me):
 340     for k in me:
 341       yield k, me[k]
 342   def keys(me):
 343     return [k for k in me]
 344   def values(me):
 345     return [me[k] for k in me]
 346   def items(me):
 347     return [(k, me[k]) for k in me]
 348 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
 349 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
 350 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
 351
 352 #----- Prime number generation ----------------------------------------------
 353
 354 class PrimeGenEventHandler (object):
 355   def pg_begin(me, ev):
 356     return me.pg_try(ev)
 357   def pg_done(me, ev):
 358     return PGEN_DONE
 359   def pg_abort(me, ev):
 360     return PGEN_TRY
 361   def pg_fail(me, ev):
 362     return PGEN_TRY
 363   def pg_pass(me, ev):
 364     return PGEN_TRY
 365
 366 class SophieGermainStepJump (object):
 367   def pg_begin(me, ev):
 368     me.lf = PrimeFilter(ev.x)
 369     me.hf = me.lf.muladd(2, 1)
 370     return me.cont(ev)
 371   def pg_try(me, ev):
 372     me.step()
 373     return me.cont(ev)
 374   def cont(me, ev):
 375     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 376       me.step()
 377     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 378       return PGEN_ABORT
 379     ev.x = me.lf.x
 380     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 381       return PGEN_DONE
 382     return PGEN_TRY
 383   def pg_done(me, ev):
 384     del me.lf
 385     del me.hf
 386
 387 class SophieGermainStepper (SophieGermainStepJump):
 388   def __init__(me, step):
 389     me.lstep = step;
 390     me.hstep = 2 * step
 391   def step(me):
 392     me.lf.step(me.lstep)
 393     me.hf.step(me.hstep)
 394
 395 class SophieGermainJumper (SophieGermainStepJump):
 396   def __init__(me, jump):
 397     me.ljump = PrimeFilter(jump);
 398     me.hjump = me.ljump.muladd(2, 0)
 399   def step(me):
 400     me.lf.jump(me.ljump)
 401     me.hf.jump(me.hjump)
 402   def pg_done(me, ev):
 403     del me.ljump
 404     del me.hjump
 405     SophieGermainStepJump.pg_done(me, ev)
 406
 407 class SophieGermainTester (object):
 408   def __init__(me):
 409     pass
 410   def pg_begin(me, ev):
 411     me.lr = RabinMiller(ev.x)
 412     me.hr = RabinMiller(2 * ev.x + 1)
 413   def pg_try(me, ev):
 414     lst = me.lr.test(ev.rng.range(me.lr.x))
 415     if lst != PGEN_PASS and lst != PGEN_DONE:
 416       return lst
 417     rst = me.hr.test(ev.rng.range(me.hr.x))
 418     if rst != PGEN_PASS and rst != PGEN_DONE:
 419       return rst
 420     if lst == PGEN_DONE and rst == PGEN_DONE:
 421       return PGEN_DONE
 422     return PGEN_PASS
 423   def pg_done(me, ev):
 424     del me.lr
 425     del me.hr
 426
 427 class PrimitiveStepper (PrimeGenEventHandler):
 428   def __init__(me):
 429     pass
 430   def pg_try(me, ev):
 431     ev.x = me.i.next()
 432     return PGEN_TRY
 433   def pg_begin(me, ev):
 434     me.i = iter(smallprimes)
 435     return me.pg_try(ev)
 436
 437 class PrimitiveTester (PrimeGenEventHandler):
 438   def __init__(me, mod, hh = [], exp = None):
 439     me.mod = MPMont(mod)
 440     me.exp = exp
 441     me.hh = hh
 442   def pg_try(me, ev):
 443     x = ev.x
 444     if me.exp is not None:
 445       x = me.mod.exp(x, me.exp)
 446       if x == 1: return PGEN_FAIL
 447     for h in me.hh:
 448       if me.mod.exp(x, h) == 1: return PGEN_FAIL
 449     ev.x = x
 450     return PGEN_DONE
 451
 452 class SimulStepper (PrimeGenEventHandler):
 453   def __init__(me, mul = 2, add = 1, step = 2):
 454     me.step = step
 455     me.mul = mul
 456     me.add = add
 457   def _stepfn(me, step):
 458     if step <= 0:
 459       raise ValueError, 'step must be positive'
 460     if step <= MPW_MAX:
 461       return lambda f: f.step(step)
 462     j = PrimeFilter(step)
 463     return lambda f: f.jump(j)
 464   def pg_begin(me, ev):
 465     x = ev.x
 466     me.lf = PrimeFilter(x)
 467     me.hf = PrimeFilter(x * me.mul + me.add)
 468     me.lstep = me._stepfn(me.step)
 469     me.hstep = me._stepfn(me.step * me.mul)
 470     SimulStepper._cont(me, ev)
 471   def pg_try(me, ev):
 472     me._step()
 473     me._cont(ev)
 474   def _step(me):
 475     me.lstep(me.lf)
 476     me.hstep(me.hf)
 477   def _cont(me, ev):
 478     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 479       me._step()
 480     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 481       return PGEN_ABORT
 482     ev.x = me.lf.x
 483     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 484       return PGEN_DONE
 485     return PGEN_TRY
 486   def pg_done(me, ev):
 487     del me.lf
 488     del me.hf
 489     del me.lstep
 490     del me.hstep
 491
 492 class SimulTester (PrimeGenEventHandler):
 493   def __init__(me, mul = 2, add = 1):
 494     me.mul = mul
 495     me.add = add
 496   def pg_begin(me, ev):
 497     x = ev.x
 498     me.lr = RabinMiller(x)
 499     me.hr = RabinMiller(x * me.mul + me.add)
 500   def pg_try(me, ev):
 501     lst = me.lr.test(ev.rng.range(me.lr.x))
 502     if lst != PGEN_PASS and lst != PGEN_DONE:
 503       return lst
 504     rst = me.hr.test(ev.rng.range(me.hr.x))
 505     if rst != PGEN_PASS and rst != PGEN_DONE:
 506       return rst
 507     if lst == PGEN_DONE and rst == PGEN_DONE:
 508       return PGEN_DONE
 509     return PGEN_PASS
 510   def pg_done(me, ev):
 511     del me.lr
 512     del me.hr
 513
 514 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
 515   start = MP(start)
 516   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
 517               nsteps, RabinMiller.iters(start.nbits))
 518
 519 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
 520   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
 521               event, 0, 1)
 522
 523 def kcdsaprime(pbits, qbits, rng = rand,
 524                event = pgen_nullev, name = 'p', nsteps = 0):
 525   hbits = pbits - qbits
 526   h = pgen(rng.mp(hbits, 1), name + ' [h]',
 527            PrimeGenStepper(2), PrimeGenTester(),
 528            event, nsteps, RabinMiller.iters(hbits))
 529   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
 530            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
 531   p = 2 * q * h + 1
 532   return p, q, h
 533
 534 #----- That's all, folks ----------------------------------------------------